Website Carbon Impact Optimisation is designed to be entirely privacy-first. The extension does not collect, store, transmit, or share any personal data or browsing information. All processing happens locally in your browser.
Data we do not collect
- We do not collect or store the URLs of pages you visit
- We do not log your browsing history
- We do not track which websites you scan
- We do not collect any personally identifiable information
- We do not use analytics, telemetry, or crash reporting
- We do not use cookies
- We do not serve advertising of any kind
Data processed locally
When you scan a page, Website Carbon Impact Optimisation reads performance data from your browser's native Performance API including page weight, resource sizes, script counts, and caching headers. This data is processed entirely within your browser to calculate a carbon score and technical audit. It is never transmitted to any server and is discarded as soon as you close the popup.
Session data (number of pages scanned and total CO₂ grams in the current session) is held in memory only and is lost when the popup closes. Nothing is written to disk or synced.
Your theme preference (light or dark mode) is stored locally in your browser using localStorage. This data never leaves your device.
The one external call we make
The only network request the extension makes is a single call to the Green Web Foundation API:
https://api.thegreenwebfoundation.org/api/v3/greencheck/{hostname}
This sends only the bare hostname of the page you are scanning, for example theforest.uk. It does not send the full URL, any page content, your IP address, or any identifying information about you.
The Green Web Foundation is an independent non-profit organisation. Their privacy policy can be found at thegreenwebfoundation.org.
Permissions we request and why
activeTab
To read the URL of the page you are currently viewing and inject the scanning script when you click the extension icon.
scripting
To inject the content script that reads Performance API data from the active page. No page content, text, or user data is read or transmitted.
tabs
To query which tab is currently active so the extension can retrieve the tab URL for display and extract the hostname for the green hosting check.
host_permissions
To make the single Green Web Foundation API call described above. No permission is used beyond its stated purpose.
Third-party services
The extension loads two resources from external CDNs when the popup opens: the Inter typeface via Google Fonts and the Phosphor icon set via jsDelivr. These are standard font and icon libraries loaded over HTTPS. Standard CDN access logs may apply on their end, but no data about you or the pages you scan is included in these requests.
Children's privacy
This extension is not directed at children and does not knowingly collect any data from anyone.
Changes to this policy
If we make material changes to this privacy policy, we will update the version published at theforest.uk. The extension version number will be incremented accordingly.
Contact
Forest Web Hosting
hello@theforest.uk
theforest.uk
Website Carbon Impact Optimisation v1.0.0 · Last updated June 2026